Rotary-hook mechanism for sewing machines



March 1930! M. L. WATERMAN 1,750,447

' ROTARY HOOK MECHANISM FOR- sawmc mcnnms Filed larch 31,-, '1928 2 Sheets-Sheet 1 INVENTOR ATTORNEY I Max L. uaferrnan wlmssgl s hq WITNESSES W March 11, 1930.- M. 1. WATERMAN 1,750,447

ROTARY HOOK HECHANISI FOR SEWING IACHINES Filed larch 31, 1928 2 Shuts-Sheet 2 v J9 J7 /,////////////////}/,g

A W J !NVENTOR fl/ax L Waterman ATTORNEY Patented Mar. 11, 1930 UNITED STATES PATENT OFFICE MAX LEON WATERMAN, 0]! FAIRFIELD, CONNECTICUT,

MANUFACTURING COMPANY, OF ELIZABETH, NEW JERSEY,

NEW JERSEY ASSIGNOB To run smear. A CORPORATION or BOTABY EOOK MECHANISM FOR SEWING MACHINES Application filed March 31, 1928. Serial N0. 266,239.

This invention relates to sewing machines of the type in which a rotary-hook or looptaker casts needle-thread loops about a thread mass within a thread-case restrained against rotation with the loop-taker.

The primary object of the present'invention is to provide an improved mechanism for effecting' an unobstructed passage for the needle-thread loops past the means employed for restraining the thread-case against rotation' with the loop-taker.

Other objects of the invention will be apparent from the following description and claims. I

In a common type of. rotary-hook mechanism, a thread-case is journaled in the hookbody and, while ittherefore has a normal tendency to rotate therewith, it is confined to limited axial oscillation by loosely interengaging stop-lug and stop-notch members provided upon the thread-case and some stationary element, such as the machine throat-plate. In order to obtain a free passage past said stop-members, the thread-case is intermit- 5 tently oscillated in a direction opposite to the direction of rotation of the hook.

To this end, the thread-case in a preferred embodiment of thetpresent invention is provided with a laterally extending lug disposed substantially in the plane of the stop-member on said thread-case. An edge of said lateral lug is disposed substantially tangential to the periphery of the thread-case and is intermittently engaged by a finger adj ustably carried by a rocker forkedto provide spaced arms fuls crumed at opposite sides of the hook-shaft to swing about an axis transverse to said shaft. The rocker preferably has a combined swivel and cushioned connection with a pitman provided with a strap embracing an eccentric upon a shaft deriving one-to-one rotation from the main-shaft of the machine and imparting two-to-one rotation to the hook-shaft. While therefore the present opener-mechanism is very durable by reason of the steadying efiect of the two-armed rocker and its one-to-one vibration with respect to the needle reciprocations, it is also comparatively to gentle in its action upon the thread-case by .tuating pitman.

In the accompanymg drawings, Fig. 1 is a longitudinal sectional view of a sewing ma-v chine containing the present improved opener-mechanism. Fig. 2 is a top plan view of the rotary hook and opener-mechanism with a sectional view of one of the supports for its detail perspective of a portion of the machine throat-plate, the thread-case and of the opener-mechanism, the pitman actuating the opener-rocker being shown partly in section. Fig. 4' is a detail sectional view of the connection between the opener-finger carrying rocker and its actuating pitman.

Referring to the drawings, the present improvement has been embodied in a sewing machine having a clothor bed-plate 1 from which rises a hollow standard 2 of a bracketactuating shaft. Fig. 3 is a arm 3, overhanging the cloth-plate and acrank-disk 7 connected in the usual manner, by means of a link 8, with a needle-bar 9. The needle-bar 9 is suitably journaled in the head 4 for endwise reciprocation and carries at its lower end a needle 10. Also journaled in the head 4 for endwise movement is the usualpresser-bar 11 carrying at its lower end a resser-foot 12 opposed to a feed-dog 13 of the lower four-motiontype and operating through slots, as 14, provided forthe purpose in a throat-plate 15, which additionally has the usual needle-aperture 16.

Depending from the cloth-plate 1 are lugs 17 and 18 provided with bearin for a rotary actuating shaft 19 parallel with the mainshaft 5 and carrying at one end a belt-pulley 20 connected by means of a belt 21 with a ulley 22 upon the main-shaft 5. The uleys 20 and 22 are of equal size and there ore the shafts 5 and 19 rotate in unison durmg the operation of the machine.

The shaft 19 adjacent its rear end is ]0111'- naled in a bushing 23 fixed by 'means of a screw 24 in a transverse aperture in the lug 17. Adjacent its forward end the shaft. 19

is journaled in a bushing 25 secured, as by means of a set-screw 26 within a tubular, integral extension 27 of a housing 28. The extension 27 of the housin is seated in a transverse aperture providef for the purpose in the lug 18 and is fixed therein by suitable securing screws.

The end of the shaft 19 extends within the chamber 28 of the housing 28 and carries a bevel-gear 29 in mesh with a similar gear 30 fixed upon a vertically disposed hook-shaft 31, the gears 29 and 30 having a ratio such that the hook-shaft 31 is rotated twice for each rotation of its actuating shaft 19. The lower end of the hook-shaft is journaled in a bushing 32 fixed by means of a set-screw 33 in a vertically directed aperture formed in the housing 28, this aperture being sealed by a headed-screw 34. Above the bevel-gear 30, an enlarged portion of the hook-shaft 31 is journaled in a bushing 35 fixed in the housing 28 by means of a set-screw 36. The upper end of the hook-shaft 31 carries a rotary-hook 37 within the cupped body of which is j o'urnaled the usual peripheral bearing-rib 38 of a thread-case 39 containing, as usual, a mass of under-thread, around which the needle-thread loops are cast by the hook in the formation of lock-stitches.

Projecting laterally from the thread-case, and substantially from the upper end of its side wall, is a stop-lug 40 loosely entering a stop-notch 41 provided in the throat-plate 15, whereby the thread-case is confined to limited axial oscillation. According to the present invention, improved means are provided for slightly oscillating the thread-case in a direction opposite to the direction of rotation of the hook, once for each needle reciprocation, in order to provide a free passage for the needle-thread loops between one of the walls of the stop-notch 41 and the stoplug 40. To this end, the thread-case is formed with a lateral projection 42, one edge 43 of which is directed substantially tangential to the side wall of the thread-case and is disposed in substantially the same horizontal plane as the stop-lug 40.

Positioned to intermittently engage the edge 43 of the projection 42 is the curved end of a horizontally disposed opener-finger 44. The shank of the opener-finger 44 is fixed in a grooved seat 45 provided in a forked rocker 46, the finger being secured for adjustment in the direction of its length by means of a screw 47 passing through an elongated slot 48 in the shank of said 'finger. The forked rocker 46 has spaced arms 49 and 50, disposed at opposide sides of the hookshaft 31 and provided with apertured bearingbosses as 51 and 52. The bosses 51 and 52 are journaled upon alined gudgeons 53 and 54, projecting from and suitably fixed in the housing 28. The ,gudgeons, 53, 54 are disposed in a line'directly under the point of contact of the opener-finger 44 with the thread-case projection 42 and thereby not only constitute a steadying support for the opener-finger but because of the location of said gudgeons, the operative end of the linger 44 has a substantially horizontal movement in its action to oscillate the thread-case.

Threaded into the rocker 46 is a screw 55 having a convex surface 56 positioned within a slightly larger but straight aperture 57 formed in a pitman 57. The pitman 57 passes through a suitable opening 58 in the top wall of the housing 28 and has at its lower end a strap 59 embracing an eccentric 60 secured upon the acuating shaft 19 within the chamber 28 of the housing 28. An upper extension of the pitman 57 is longitudinally apertured to receive a coil-spring 61, interposed between an adjusting screw 62 threaded into the upper end of the pitman and a ball bearing upon the convex surface 56 of the screw 55. This construction provides a cushioned swivel-joint in connection between the rocker 46 and its actuating pitman 57, not only allowing for the slight swinging movements of the rocker 46 about its horizontal fulcrum and the lateral vibration of the pitman 57 about the screw 56, but also permitting the connection -to slightly yield during the movement of the finger 44 to engage the thread-case projection 4 The construction described permits of assembly of the hook and opener-mechanism, including the actuating shaft 19, in the housing 28 as a unit independently of the rest of the machine, which unit may be readily applied to. or removed from the machine.

The chamber 28 of the housing 28 comprises a lubricant reservoir preferably containing sufiicient lubricant to partially immerse the bevel-gear 29, which accordingly acts as a splasher within the housing. The hook-shaft 31, above the bevel-gear 30, is provided with a spiral groove 63 which serves to conduct the lubricant to the upper bearing surface of said shaft, while at its lower end the hook-shaft is provided with a groove 64 to conduct the lubricant to the lower bearing of said shaft. The lubricant is supplied through a ball-valve controlled opening 65 in the upper side of the cloth-plate 1, passing through a duct 66 in the bearing-lug 18 and a connecting duct 67 in the housingextension 27 into a groove 68 disposed lengthwise of the upper surface of the bushing 25. A series of small ducts, as 69, serve to lead lubricant from the groove 68 into the shaftbearing aperture of the bushin'g25, the remainder ofthe lubricant passlng into the chamber of'the housing 28.

Likewise the rear bearing of the shaft 19 may be lubricated from above the cloth-plate by forming a supply opening 71 in the stand ard 2, the lubricant being collected by a depression 72 in the upper surface of the bedinvention, what I claim herein is 1. In a sewing machine, a reciprocatory needle, a rotary hook cooperating with said needle in the formation of lock-stitches, a

thread-case journaled in said rotary hook, stationary means for limiting oscillation of said thread-case in one direction, an openerfinger having a thread-case engaging portion movable in a general direction crosswise o the axis of rotation-of the hook to oscillate said thread-case in a direction away from said stationary means, means for pivotally supporting said opener-finger upon an axis transverse to the axis of rotation of the hook, and means for actuating said finger.

' 2. In a sewing machine, a reciprocatory needle, a rotary hook cooperating with said needle in the formation of lock-stitches, a thread-case journaled in said rotary hook, stationary means for limiting oscillation of said thread-case in one direction, an openerfinger adapted toengage said thread-case to oscillate it in a direction away from said stationary means, said opener-finger having a pivotal axis intersected by a straight line substantially parallel with the axis of rotation of the hook and passing through the point of engagement of the opener-finger with the thread-case, and means for actuating said finger.

3. In a sewing machine, a reciprocatory needle, a rotary hook cooperating with said needle in the formatio of lock-stitches, a thread-case journaled in said rotary hook, means for confining the thread-case to limited oscillation, an opener-finger adapted to engage the thread-case to oscillate it in one direction, a pivotal rocker carrying said openerfinger, a reciprocatory pitman, a cushioned swivel-connection between said rocker and the pitman, and means for reciprocating said pitman,

4. In a sewing machine, a reciprocatory needle, a rotary hook cooperating with said needle in the formation of lock-stitches,.a thread-case journaled in said rotary hook, means for restraining said thread-case against rotation with the hook, means for oscillating the thread-case in a direction opposite to the direction of rotation of the hook including an opener-finger, a rocker carrying said opener-finger, pivotal supports for said rocker at opposite sides of said hook, and means for actuating said rocker.

5. In a sewing machine, a reciprocatory needle, a hook rotating about a substantially vertical axis for cooperation with said needle in the formation of lock-stitches, a threadcase 'ournaled in said hook, stationary means for limiting oscillation of the thread-case 1n one direction about a vertical axis, an openerfinger having a thread-case engaging portion movable in a general direction crosswise of the axis of rotation of the hook to oscillate the thread-case in a direction away from said stationary means, a horizontal-axis pivotal support for said opener-finger, and means for actuating said finger.

6. In a sewing machine, a needle, means for reciprocating said needle, a hook rotating about a substantially vertical axis for cooperation with said needle in the formation of lock-stitches, means for imparting a plurality of rotations to said hook for each needle reciprocation, a thread-case journaled in said hook, stationary means for limiting oscillation of the thread-case in one direction about a vertical axis, an opener-finger adapted to engage said thread-case to oscillate it in.

a direction away from said stationary means, a 'rocker carrying said opener-finger having spaced arms fulcrumed at opposite sides of the hook-axis, and means for oscillating said rocker once for each needle reciprocation.

7. In a sewing machine, a needle, means for reciprocating said needle, a hook performing a plurality of rotations for each needle reciprocatiom'a thread-case journaled in said hook, means for restraining the thread-case against rotation with said hook, an opener-finger adapted to turn the thread case in a direction opposite to the direction of rotation of the book, a rocker carrying said finger, a pivotal support for said rocker upon opposite sides of the hook, a reciprocatory pitman, a universal-joint connection between said pitman and the rocker, and means for reciprocating said pitman once for each needle reciprocation.

8. In a sewing machine having a clothplate, a reciprocatory needle, housing detachably secured to the machine frame beneath said cloth-plate, a rotary-hook carrying shaft journaled in said housing, a thread-case journaled in the rotary hook carried by said shaft,-means confining the threadcase to limited oscillation, an actuating shaft j ournaled in said housing and extending within the chamber thereof, gear connections between said shafts within the housing-chamber for imparting a plurality of rotations to the hook-shaft for each rotation of the actuating shaft, an opener-finger adapted to engage the thread-case to oscillate the same, a pivotal support for saidopener-finger upon the housing, and means directly connected with, said actuating shaft within the housing-chamber for operating said opener-finger.

9. In a sewing machine having a clothplate, a reciprocatory needle, a chambered housing detachably secured to the machine frame beneathsaid cloth-plate, a vertically disposed rotary-hook carrying shaft journaled in said housing a thread-case journaled in the rotary-hook carried by said shaft, means for restraining the thread-case against rotation with said rotary-hook, a horizontally disposed actuating-shaft journaled in said housing and extending within 5 the chamber thereof, gear-connection between said shafts within the housing-chamher for imparting a plurality of rotations to the hook-shaft for each rotation of the actuating shaft, an opener-finger adapted to engage the thread-case to oscillate it in a direction opposite to the direction of rotation of the rotary-hook, a pivotal support for said opener-finger upon the housing, means directly connected with said actuating shaft Within the housing-chamber for operating said opener-finger, and .means for conducting lubricant through the machine cloth-plate to the actuating-shaft bearing in said housing, to the chamber within said housing and from 2 said chamber to the housing bearings for the vertically disposed hook-carrying shaft.

In testimony whereof, I have signed my name to this specification.

MAX LEON vVATERMAN. 

